Caroline Cox has introduced a bill to the House of Lords that would have the effect of curbing sharia tribunals by making it clear that they have no authority in law to deal with family or criminal matters (including domestic violence). Lady Cox's bill is backed by Christians and secularists. But is it necessary? Will it have positive effects? Or will it simply raise prejudice against Muslims? And it is possible to have a form of sharia that is compatible with our views on equality: can any good come from a code in which a woman's evidence is automatically worth half a man's?